Machining
6061-T6511, 2011-T3 and 7075-T651 machine best. Sharp carbide tools, high speeds and coolant prevent built-up edge on softer 6063.
Long products
Aluminium Flat Bar: Grades & Sizes
Aluminium flat bar is a solid rectangular section, usually extruded, used for frames, brackets, machined parts, busbars and trim. The main grades are 6061-T6 and 6082-T6 for structural and machined parts, 6063-T5/T6 for architectural work, and 2024, 7075 and free-machining 2011 for high-strength or high-volume machining. Metline supplies flat bar in metric and imperial sizes, cut to length and certified, to customers worldwide.
- Grades
- 6061, 6063, 6082, 2024, 7075
- Tempers
- T5, T6, T6511, T351, T651
- Weight
- 0.0027 kg/m per mm² of section
- Standards
- ASTM B221 · B211 · EN 755
What is aluminium flat bar?
Flat bar is the simplest aluminium section: a solid rectangle wider than it is thick. It is cheap, easy to cut, drill and weld, and is the default stock for brackets, straps, spacers, wear strips and anything that will be machined from a rectangular blank.
Most flat bar is extruded and then stretched to straighten it, which gives slightly rounded corners and an as-extruded surface. Where tighter tolerances and sharper corners are needed, bar is cold finished by drawing through a die. Very wide or thick flats, and grades that are rarely extruded, are sawn from plate; these have sharp sawn edges and the properties of the plate they are cut from.
In stretched tempers such as T6511 and T351, residual stresses are relieved, so the bar stays straight and flat when material is machined off one face. That makes these tempers the preferred choice for precision parts, while T6 and T5 are fine for frames and fabrication.
Flat bar grades and typical properties
| Alloy and temper | Tensile strength (typ.) | Yield strength (typ.) | Character and use |
|---|---|---|---|
| 6063-T5 / T6 | 185 / 240 MPa | 145 / 215 MPa | Architectural trim, frames, best anodised finish |
| 6061-T6 / T6511 | 310 MPa | 276 MPa | General engineering, structural and machined parts |
| 6082-T6 | 310 – 340 MPa | 260 – 300 MPa | European and Indian structural grade |
| 2011-T3 | 379 MPa | 296 MPa | Free-machining bar for high-volume turned and milled parts |
| 2014-T6 / T651 | 483 MPa | 414 MPa | High-strength machined and structural parts |
| 2017-T4 / T451 | 427 MPa | 276 MPa | Fittings and fasteners |
| 2024-T3 / T351 | 470 – 483 MPa | 325 – 345 MPa | Aircraft fittings, high fatigue strength parts |
| 7075-T6 / T651 | 572 MPa | 503 MPa | Highest-strength bar for aerospace, moulds and tooling |
Typical values from Aluminum Association and producer data. Specified minimums in ASTM B221, B211 and EN 755-2 are lower and depend on thickness; design to the minimum shown on the certificate.
2xxx and 7xxx bars have poorer corrosion resistance and are not suitable for fusion welding. For welded frames, choose 6061, 6063 or 6082. 2011 contains lead and bismuth for chip-breaking; lead-free 2011B or 6262 is used where RoHS rules apply.
Flat bar sizes and weights
Weight per metre equals width × thickness (in mm) × 0.0027 kg. The table gives common sizes; use the bar weight calculator for any other.
| Width × thickness (mm) | Weight (kg/m) | Weight per 6 m length (kg) |
|---|---|---|
| 20 × 3 | 0.162 | 0.97 |
| 25 × 5 | 0.338 | 2.03 |
| 30 × 6 | 0.486 | 2.92 |
| 40 × 8 | 0.864 | 5.18 |
| 50 × 10 | 1.350 | 8.10 |
| 60 × 10 | 1.620 | 9.72 |
| 80 × 12 | 2.592 | 15.55 |
| 100 × 10 | 2.700 | 16.20 |
| 100 × 20 | 5.400 | 32.40 |
| 150 × 25 | 10.125 | 60.75 |
| 200 × 30 | 16.200 | 97.20 |
Typical supply range
- Thickness
- About 2 – 100 mm extruded; thicker from plate
- Width
- About 10 – 300 mm extruded; wider from plate
- Imperial sizes
- 1/8 × 1/2 in up to 4 × 12 in
- Lengths
- 3 m, 4 m, 6 m, 12 ft, or cut to length
- Finish
- Mill, anodised, brushed, powder coated
Some size and grade combinations are produced to order; we confirm with the quotation.
Standards and tolerances
| Purpose | ASTM / AMS | EN / international |
|---|---|---|
| Extruded bar | ASTM B221; AMS-QQ-A-200 series | EN 755-2 (properties) |
| Cold-finished bar | ASTM B211 | EN 754-2 |
| Tolerances, rectangular bar | ANSI H35.2 | EN 755-5 (extruded); EN 754-5 (drawn) |
| Chemistry | Aluminum Association | EN 573-3 |
| Electrical flats | ASTM B317 (6101 bus conductor) | EN 14121 / IEC requirements |
Extruded flat bar under EN 755-5 has width and thickness tolerances that widen with size, together with limits on corner radius, flatness and twist. Cold-drawn bar under EN 754-5 is closer. If your part is machined on all faces, normal extruded tolerances are usually adequate and cheaper; if the bar is used as-supplied in an assembly, state the critical tolerances on the order.
Machining, welding, bending and finishing
Welding
6xxx bars weld with ER4043 or ER5356; expect strength loss in the heat-affected zone. Avoid welding 2xxx and 7xxx.
Bending
Bend 6063 and 6061 the easy way with radii of 1 – 3 × thickness; bending on edge needs larger radii or annealed material.
Anodising
6063 gives the best appearance; 6061 and 6082 anodise well for industrial parts.
Where aluminium flat bar is used
- Construction: handrails, balustrades, door thresholds, frames and stiffeners
- Transport: trailer and truck body rails, rub strips and brackets
- Machinery: guards, mounting plates, jigs, fixtures and wear strips
- Electrical: busbars, earthing strips and switchgear connections
- Aerospace and defence: fittings and machined parts in 2024 and 7075
- Marine: deck fittings and stiffeners in 6061, 6082 or 5083 cut from plate
How to order aluminium flat bar
- SpecifyGrade and temper, width, thickness, length, quantity, standard and any tolerance or finish requirement.
- QuoteWe confirm availability, route (extruded, drawn or plate-cut), certification and terms (EXW, FOB, CIF or DAP).
- ProcessCutting to length, deburring and finishing as ordered.
- DocumentMill test certificate to EN 10204 3.1.
- ShipBundled with paper or film interleaving, in wooden cases or crates for export.
References and standards
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- ASTM B211 – Aluminum and Aluminum-Alloy Rolled or Cold-Finished Bar, Rod, and Wire
- EN 755-5 – Extruded rectangular bars: tolerances on dimensions and form
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
Aluminium (aluminum) flat bar: FAQ
How do I calculate the weight of aluminium flat bar?
Multiply width × thickness in millimetres by 0.0027 to get kg per metre. A 50 × 10 mm bar weighs 1.35 kg/m, or 8.1 kg for a 6 m length.
What is the strongest aluminium flat bar?
7075-T6 or T651 is the strongest common grade, with typical tensile strength around 570 MPa. It is used for aerospace and tooling parts but cannot be fusion welded.
6061 or 6063 flat bar?
Choose 6063 for appearance, anodising and light frames. Choose 6061 (or 6082) when the bar carries load or is machined, because it is about 30 % stronger.
What does T6511 mean on flat bar?
T6511 is solution heat-treated, stretched to relieve stress (with minor straightening allowed) and artificially aged. The bar stays straight when machined.
Can flat bar be supplied cut to size?
Yes. Flat bar can be cut to exact lengths and deburred, and wide or thick strips can be sawn from plate.
Need aluminium flat bar?
Send the grade, size, length and quantity. We will reply with availability, certification and a delivered price.
